Women in the cross hairs

Alan, Dallas — Fri, 02 Jan 2009 22:04:03 GMT

Actually the Zune issue was not seconds, though they don't handle a day having more than exactly 24 hours. The problem was with them accounting for days. The 31st was the 366th day of the year, and line 265 goes in to an infinite loop... it IS a leap year, but the days are not greater than 366, so it keeps looping without subtracting days to be able to break out of the loop.

Women in the cross hairs

foo — Fri, 02 Jan 2009 22:20:26 GMT

The Zune bug is because of the leap year. It has nothing to do with the leap second. The bug will happen every leap year.

Women in the cross hairs

Fri, 02 Jan 2009 22:22:25 GMT

The difference at Nassau Coliseum, though, is that the ice rink doesn't have to be rebuilt -- it's always there. For other events, they put a floor covering over the ice, then put the mud or turf or whatever on top of that.

Women in the cross hairs

Will Femia — Sat, 03 Jan 2009 00:11:07 GMT

Ah, I see. Thanks guys. I saw that there was a consideration of leap year in the code and figured that covered that. So specifically it's line 267 that's the real problem with that incorrect greater than?

if (days > 366)

Women in the cross hairs

Robbi, Boston — Sat, 03 Jan 2009 11:53:13 GMT

Great link to Target Women, Will. I don't normally watch commerials thanks to hubby and his TiVo, so these were laugh out loud funny to see from the host's perspective!

Women in the cross hairs

KRW — Sun, 04 Jan 2009 16:25:01 GMT

Will, yes if the days variable is exactly 366 then you will stay in the "while" loop forever since 366 will always be greater than 365 but you will never fall into either of the "if/else" conditions since for that 366 value it will never "not be a leap year" nor will the days value ever exceed 366.

The greater question is was this code ever properly reviewed? I see how this could slip by in a casual review but it would be fairly obvious to someone whose job it is to just review code (a position I would expect a large "professional" organization like M$ to have). But really the even greater question is why re-write code to do date functioning when there should be plenty of time-tested code already out there. This problem definitely never should have cropped up in this day and age.

Women in the cross hairs

Will Femia — Mon, 05 Jan 2009 03:25:27 GMT

KRW, that's what I was wondering too. They don't have boilerplate code for clocks and timers? Seems like that's something they more sort of paste in rather than write out.

Women in the cross hairs

Scott, Raleigh, North Carolina — Mon, 05 Jan 2009 15:45:55 GMT

Here's a time lapse of the RBC center in Raleigh, NC going from a NC State Basketball game to a Carolina Hurricanes ice hockey game in less than an hour and a half.

http://www.youtube.com/watch?v=Z-8hubpvhVw

Women in the cross hairs

KRW — Mon, 05 Jan 2009 17:05:25 GMT

Will, it's not even a matter of boilerplate code really. I don't know what the underlying platform is for Zune but it being M$ and possibly on a 386-type structure, you could probably even use the same compiled libraries. Even if the platform is different, you could still use the original source code and only need to tweek the variables that are platform specific. The basic logic would not need to change. And there was nothing in this function that would have been affected by that. It's definitely cut-and-paste code at the very least...Assuming one had access to the original source, which may be the real reason it was being re-invented...ah, who knows.

The primary coding issue here is the use of literal constants 365 and 366. These should be replaced with a variable named something like daysInThisYear which would be set to 365 or 366 based on IsLeapYear returning true/false. Other code changes would be required of course, but the flaw in the thinking is in the assumption made about the value 365 always meaning "a year" in the while loop logic.

Though the simplest solution would be to just break out of the loop if IsLeapYear is true and days > 366 is false. Aren't you glad these guys aren't writing the software to pump drugs into your veins or land your next red-eye airline flight?